In order to improve the excavation work efficiency at mines, an excavator needs to fill a dump with the prescribed number of excavations. Therefore, if the excavation amount per one time can be grasped, an operator can adjust the next amount to be excavated.
As a technique in taking this point into consideration, there is a technique that measures a volume by imaging an excavated object in a bucket by a stereo camera. For example, PTL 1 describes a method of calculating an amount loaded in the bucket by including a plurality of cameras on left and right side portions of a boom or left and right side portions of an arm and imaging the bucket by a camera located at substantially directly above the bucket.
However, in PTL 1, it is not assumed to estimate a blind spot region because the amount loaded in the bucket at the time of excavation is calculated by imaging when the bucket is moved to a position in which blind spot is not generated.
On the other hand, there are PTL 2 and PTL 3 as technologies for estimating the blind spot region. PTL 2 generates supplementary image data for supplementing a blind spot portion based on blind spot information estimated from a visible image portion of another vehicle included in a vehicle surrounding image obtained by a camera. In PTL 3, a slit image is captured by a camera when a measurement target is irradiated with the slit light, the volumes for each slit image are calculated, and the volumes are integrated to obtain the entire volume. In a case where the blind spot is generated in the slit image, correction is performed by previous and after data of the obtained data and data which cannot be obtained at the blind spot can be generated.